Ideal Body Weight: How Much Should I Weigh?

Body weight is measured in pounds (lbs.) or kilograms (kg.). One kg equals 2.2 lbs. Not long ago, ‘ideal’ body weight was standardized to a basic calculation based upon sex and height. The recommendations were that a woman 5-foot tall should be 100 lbs. and carry an additional 5 lbs. for every inch beyond 5 feet. For a 5-foot tall man, recommended body weight started at 106 lbs. with an additional 6 lbs. for every inch beyond 5 feet. This information was available through height-weight charts in your physician’s office.

These days, determining your ideal body weight ‘range’ is more appropriate and flexible than the older method. Factors beyond height and gender, such as age, muscle-fat ratio and bone density/frame size will influence your healthy weight. Thus, what feels good, looks good and is the best weight for you might be toward the upper or lower end of the normal range and may change over your lifespan.

How much should I weigh?

Body Mass Index (BMI), based upon your weight in relation to your height, is the most widely used calculation for determining weight appropriateness, even though it has limitations. When used along with the waist-to-hip ratio (WHR) calculation, BMI is considered, by most health experts, to be a useful tool for gauging a normal body weight for most Americans. It is calculated by dividing your weight (in kg.) by your height in meters. In imperial units, you multiply your weight (in lbs.) by 703 and then divide that number by your height squared (in inches). Downloadable BMI calculator can do the work for you.

A BMI of 18.5 to 24.9 is considered to be normal. A BMI reading of 25.0 to 29.9 puts you in the overweight category, while a BMI reading of 30 or above indicates obesity. Keep in mind that BMI does not directly measure body fat percentage.

What is a healthy weight for my height?

Never compare yourself to family, friends and/or your peers. If you are surrounded by overweight or obese individuals, you might aim too high. On the other hand, if you work in the fashion industry, surrounded by ultra-thin models, you will likely aim too low. The Centers for Disease Control and Prevention (CDC), along with the U.S. Department of Health and Human Services compiled data to determine median (average) body mass index and height-for-age data for American adults.

A weight (within the normal BMI range) for an adult male, 5 ft. 9 in. (average height) is 125 to 168 lbs. with a median weight of 153 lbs. or a BMI of about 22.5. A weight range for an adult female, 5 ft. 4 in. (average height) is 108 to 145 lbs. with a median weight of 125 lbs. or a BMI of 21.5.  Men can go higher on the BMI scale since they have more muscle mass than women. Thus, for every height there is a normal BMI weight range. Your mid-point, a BMI of 21.5 to 22.5, is one way to estimate a healthy body weight.

Keep in mind that BMI is not appropriate for body-builders and certain athletes as they have so much muscle mass and fall (incorrectly) into the ‘overweight’ category. By the same token, you might have a normal BMI reading, but be flabby, with little muscle tone. A normal BMI alone does not correspond to your fitness level or health status.

What about waist-to-hip ratio (WHR) and body fat percentage?

With its limitations, BMI alone is not the most useful tool for evaluating health. ‘Apple’ shaped individuals, or those that carry extra weight around their middle (versus on the hips and thighs) have a high WHR, which is linked to cardiovascular health problems. WHR is calculated by taking your waist measurement (at the smallest circumference) and dividing that number by your hip circumference (at the widest part). For men, a WHR of 0.9 or less is optimal, and for women, a WHR of 0.8 or less.

Your body fat percentage is calculated by dividing the weight of your body fat by your total weight. Unfortunately, most methods of estimating body fat are not very accurate. Many fitness professionals use skin caliper measurements, which are taken at specific areas of the body, and accept the margin of error. Your total body fat is composed of essential fat (10 to 12% for women and 2 to 4% for men), or the fat you need to survive, and storage fat, or the fat accumulation that protects internal organs and is stored in adipose tissue. According to the American Council on Exercise (ACE) fit individuals (non-athletes) should carry less fat than is acceptable, 21 to 24% for women and 14 to 17% for men. A total body fat percentage of greater than 31% for women or 25% for men is too high.

REFERENCES

• Centers for Disease Control and Prevention (CDC) – National Health and Nutrition Examination Survey: Healthy weight, overweight, and obesity among U.S. adults (07/03). PDF
• National Institutes of Health – National Heart Lung and Blood Institute (NHLBI): Body Mass Index (BMI) calculator
• University of Texas Southwest Medical Center: Current News Release – August 13, 2007. Waist-to-hip ratio may better predict cardiovascular risk than body mass index.
• American Council on Exercise (ACE) GetFit: Percent Body Fat Calculator (Skin Fold Method).